<?php
/**
 * Created by PhpStorm.
 * User: User
 * Date: 2017/9/20
 * Time: 9:15
 */
?>
<html>
<body>
<form action="cal1.php" method="get">
    <input typc="text" name="num1" value="<?php echo $num1?>"/>
    <select name="op">
        <option value="+">+</option>
        <option value="-">-</option>
        <option value="*">*</option>
        <option value="%">%</option>
    </select>
    <input type="text" name="num1" value="<?php echo $num2?>"/>
    =
    <input type="text" name="result"/>
    <button type="submit">计算</button>
    </form>
</body>

</html>